This invention relates generally to signal processors and more particularly to digital signal processors which are adapted for use in small lightweight radar-guided missiles.
As is known in the art, lightweight radar-guided missiles may be guided to a desired target by processing various received signals, such as radar echo signals, and applying such processed signals to the missile's flight control mechanism thereby to enable a successful intercept. Generally such a missile includes an autopilot for developing these proper flight control mechanism signals. Known autopilots include integrators and summing amplifiers which combine outputs from various missile mounted measuring instruments, such as gyros and accelerometers, in a desired manner to stabilize and guide the missile. In order for such an autopilot to operate efficiently over a wide range of aerodynamic conditions it is generally required that different gains and time constants of integrators and amplifiers be used when the missile travels in different regions of its operating range. Further, in known radar-guided missiles analog signal processing techniques are generally used to process radar echo signals. For example, a radar system generally detects a target in a noise or clutter environment by discriminating between the Doppler frequency of the target and the Doppler frequency of the noise or clutter. One technique which may be used in such frequency discrimination techniques is through the use of analog signal processing equipment which may include a swept local oscillator and an analog frequency tracking feedback control system.
The analog signal processing techniques used to process the echo signals and used in the autopilot to develop proper flight control mechanism signals are sometimes limited by the degree of their processing versatility and sophistication which may ultimately lead to an unsuccessful missile-target engagement. Many of these limitations may be overcome by using digital signal processing techniques; however, it is necessary that the digital signal processor operate in "real time" and have minimum weight and volume in order to be practical for application in a small lightweight radar-guided missile.